Re: [PATCH 1/2] dts: socfpga: Add bindings for Altera SoC SDRAM controller

[Steffen Trumtrar <s.trumtrar@pengutronix.de>]

Hi!

On Tue, Apr 01, 2014 at 03:11:41PM -0500, Thor Thayer - Sendmail wrote:
> On Tue, 2014-04-01 at 07:28 +0200, Steffen Trumtrar wrote:
> > Hi!
> > 
> > On Mon, Mar 31, 2014 at 05:07:06PM -0500, tthayer@altera.com wrote:
> > > From: Thor Thayer <tthayer@altera.com>
> > > 
> > > Addition of the Altera SDRAM controller bindings and device
> > > tree changes to the Altera SoC project.
> > >
> 
> <snip>
> 
> > > diff --git a/Documentation/devicetree/bindings/arm/altera/socfpga-sdram.txt b/Documentation/devicetree/bindings/arm/altera/socfpga-sdram.txt
> > > new file mode 100644
> > > index 0000000..351ab7b
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/arm/altera/socfpga-sdram.txt
> > > @@ -0,0 +1,14 @@
> > > +Altera SOCFPGA SDRAM Controller
> > > +
> > > +Required properties:
> > > +- compatible : "altr,sdr-ctl", "syscon";
> > > +                Note that syscon is invoked for this device to support the FPGA
> > > +		bridge driver and possibly other devices in the future.  See
> > > +		also Documentation/devicetree/bindings/mfd/syscon.txt
> > 
> > This note is really linux specific (and specific to some vendor kernel driver
> > for that matter). I think you should remove that.
> 
> Hi Steffen. Are you asking for the path to syscon.txt to be removed or
> the entire note? 
> The note is explaining why the "syscon" tag is used for this Altera IP
> block (registers shared between multiple drivers).
> Thanks for the clarification.
> 

I was referring to the note. I don't know what the current guideline is for
this type of "devices", but I think referring to the syscon documentation
is okay.
The first part however describes a DT binding with things that might or might
not happen in the future. What I want to say is, I would rather have this
reworded, to have it just describe the SDRAM controller node as simple as it may
be.

> > 
> > > +- reg : Should contain 1 register ranges(address and length)
> > > +
> > > +Example:
> > > +	sdrctl@0xffc25000 {
> > > +		compatible = "altr,sdr-ctl", "syscon";
> > > +		reg = <0xffc25000 0x1000>;
> > > +	};
> > > diff --git a/arch/arm/boot/dts/socfpga.dtsi b/arch/arm/boot/dts/socfpga.dtsi
> > > index 9e78c1d..3634de7 100644
> > > --- a/arch/arm/boot/dts/socfpga.dtsi
> > > +++ b/arch/arm/boot/dts/socfpga.dtsi
> > > @@ -528,6 +528,11 @@
> > >  			reg-io-width = <4>;
> > >  		};
> > >  
> > > +		sdrctl@0xffc25000 {
                       ^^
Oh, and Dinh just mentioned in my patch, that the 0x shall be removed here.
But I'm not so sure about that. Just FYI.

> > > +			compatible = "altr,sdr-ctl", "syscon";
> > > +			reg = <0xffc25000 0x1000>;
> > > +		};
> > > +
> > >  		rstmgr@ffd05000 {
> > >  			compatible = "altr,rst-mgr";
> > >  			reg = <0xffd05000 0x1000>;

Regards,
Steffen

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